[Qemu-devel] [PATVH v2] net: ne2000: fix bounds check in ioport operations

[P J P <ppandit@redhat.com>]

From: Prasad J Pandit <pjp@fedoraproject.org>

While doing ioport r/w operations, ne2000 device emulation suffers
from OOB r/w errors. Update respective array bounds check to avoid
OOB access.

Reported-by: Ling Liu <liuling-it@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/net/ne2000.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

Updated as per review in
  -> https://lists.gnu.org/archive/html/qemu-devel/2015-12/msg04856.html

diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c
index 010f9ef..d1f764b 100644
--- a/hw/net/ne2000.c
+++ b/hw/net/ne2000.c
@@ -447,8 +447,7 @@ static uint32_t ne2000_ioport_read(void *opaque, uint32_t addr)
 static inline void ne2000_mem_writeb(NE2000State *s, uint32_t addr,
                                      uint32_t val)
 {
-    if (addr < 32 ||
-        (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
+    if (addr < 32 || (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
         s->mem[addr] = val;
     }
 }
@@ -457,9 +456,10 @@ static inline void ne2000_mem_writew(NE2000State *s, uint32_t addr,
                                      uint32_t val)
 {
     addr &= ~1; /* XXX: check exact behaviour if not even */
-    if (addr < 32 ||
-        (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
-        *(uint16_t *)(s->mem + addr) = cpu_to_le16(val);
+    if (addr < 32
+        || (addr >= NE2000_PMEM_START
+            && addr + sizeof(uint16_t) < NE2000_MEM_SIZE)) {
+        *(uint16_t *)(s->mem + addr) = cpu_to_le16(data);
     }
 }
 
@@ -467,16 +467,16 @@ static inline void ne2000_mem_writel(NE2000State *s, uint32_t addr,
                                      uint32_t val)
 {
     addr &= ~1; /* XXX: check exact behaviour if not even */
-    if (addr < 32 ||
-        (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
+    if (addr < 32
+        || (addr >= NE2000_PMEM_START
+            && addr + sizeof(uint32_t) < NE2000_MEM_SIZE)) {
         stl_le_p(s->mem + addr, val);
     }
 }
 
 static inline uint32_t ne2000_mem_readb(NE2000State *s, uint32_t addr)
 {
-    if (addr < 32 ||
-        (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
+    if (addr < 32 || (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
         return s->mem[addr];
     } else {
         return 0xff;
@@ -486,8 +486,9 @@ static inline uint32_t ne2000_mem_readb(NE2000State *s, uint32_t addr)
 static inline uint32_t ne2000_mem_readw(NE2000State *s, uint32_t addr)
 {
     addr &= ~1; /* XXX: check exact behaviour if not even */
-    if (addr < 32 ||
-        (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
+    if (addr < 32
+        || (addr >= NE2000_PMEM_START
+            && addr + sizeof(uint16_t) < NE2000_MEM_SIZE)) {
         return le16_to_cpu(*(uint16_t *)(s->mem + addr));
     } else {
         return 0xffff;
@@ -497,8 +498,9 @@ static inline uint32_t ne2000_mem_readw(NE2000State *s, uint32_t addr)
 static inline uint32_t ne2000_mem_readl(NE2000State *s, uint32_t addr)
 {
     addr &= ~1; /* XXX: check exact behaviour if not even */
-    if (addr < 32 ||
-        (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
+    if (addr < 32
+        || (addr >= NE2000_PMEM_START
+            && addr + sizeof(uint32_t) < NE2000_MEM_SIZE)) {
         return ldl_le_p(s->mem + addr);
     } else {
         return 0xffffffff;
-- 
2.4.3